Process of and apparatus for centrifugal casting



July 31, 1928. 1,678,641

A J. HoL'rHAqs A PROCESS OF AND APPARATUS FOR ENTRIFUGAL CASTING Filed Aug. 25, 1925 v In 1 612 for Job a H01 Zh aus v attorney- Patented July 31, 1928.

UNITED STATES PATENT OFFICE.

J'OHANN HOLTHAUS, OF. GELSENKIRCHEN, GERMANY, ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 CENTRIFUGAL PIPE CORPORATION, A CORPORATION OF DELAWARE.

PROCESS OF AND APPARATUS FOR CENTRIIUGAL CASTING.

Application filed August 25, 1925, Serial No. 52,385, and in Germany October 22, 1924.

In the known process of centrifugally casting tubes and other hollow bodies by means of a metal or so-called permanent mold, and a relatively displaceable spout the mold and the spout through which the metal runs into it are somewhat inclined to the horizontal. This is necessary to convey the liquid metal with a suitable velocity through the spout to the mold. Heretofore the inclination of such a mold has remained unchanged during the operation, and the metal has a tendenc to flow towards the lowest part of the mo d, so that, if the flow through the spout remains "constant, the part cast in the latter part of the operation is thinner than that part cast in the earlier stages.

According to this invention this disadvantage is avoided by reducing the inclination of the mold in the course of the operation, so that it approaches the horizontal position. The change of position may, preferably, proceed beyond this, so that ultimately the inclination is reversed. The rate at which the spout is withdrawn from the mold, or the mold is removed from the spout may be reduced toward the end of the casting operation, so that the spout can be completely emptied, the reduced rate of flow of the metal from the spout into the mold being compensated for by the slower movement of these two parts in relation to each other. By this the invention is advantageously distinguished from the known centrifugal casting machines of the above type in which the last portion of the liquid metal running outside the mold from the spout is wasted.

An example of aisuitable apparatus according to the invention is shown in the accompanying drawing.

In the drawing a designates a ladle, and b a gutter, the latter feeding the spout c, which is inclined and fixed. The inclination of the spout 0 is at the start approximately equal to that of the axis of the mold cl, which surrounds it and is supported on a run-way e. During the casting operation the mold is moved along the run-way, whereby its inclination is first reduced to zero, and then reversed. It is evident, that thereby continuous flowing of the liquid metal, by gravity, to the first cast portion, i. e. to the lowerpart of the mold cannot take place. In contradistinction to this ob- .jectionable eifectof prior centrifugal casting machines, by gradually changing the position of the mold to a horizontal position according to the invention there is obtained a thoroughly uniform thickness of the casting-walls, if the rate of change is appropriof the mold at the beginning of the casting o oration is reversed, may be arranged so t at it can be lowered to a'position in which the mold is in alinement with the position it occupied at the start. This is convenient for removing the casting from the mold without running the latter back to its startmg position. The removal may be eifected by holding the casting fast and then run nmg the mold back.

I have not illustrated the mechanism for rotating and traversing the mold because such mechanism is well known in the art and forms no part of the present invention.

What I claim as my invention and desire to' secure by Letters Patent of the United States is 1. The process of centrifugally casting hollow metal bodies which comprises pouring the liquid metal into an inclined mold, and during solidification of the metal, reducing the angle of inclination of the mold to zero and then reversing it.

2. The process of centrifugally casting hollow metal bodies which comprises pouring .the liquid metal into an inclined mold, and

during the pouring operationfirst reducing the angle of inclination of the mold to zero and then reversing it.

3. The process of centrifugally casting hollow metal bodies which comprises pouring the liquid metal from a spout into an inclined mold, and, during the pouring operation while the metal is solidifying, withdrawing the mold relative to the spout while reducing the angle of inclination of the mold.

4. The process of centrifugally casting hollow metal bodies which comprises pouring the liquid metal from a spout into an inclined mold, and, during the pouring operation while the metal is solidifying, withdrawing the mold relative to the spout while reducing the angle of inclination of the mold, the rate of removing'the mold being reduced toward the end, of the operation.

5. The process of centrifugally casting hollow metal bodies which comprises pouring the liquid metal from a spout into'an inclined mold, and withdrawing the mold. relative to the spout during the pouring operation while the metal is solidifying, at the same time first reducing the angle of inclination of the mold to zero and then reversing it. i

6. Apparatus for centrifugally casting hollow metal bodies comprising an inclined mold, an inclined pouring spout extending into the mold, the mold being movable longitudinally relatively to the spout, and means for reducing the angle of inclination of the I mold during the relative movement of the mold and the spout.

7. Apparatus for centrifugally casting hollow metal bodies, comprising a movable mold, a pouring spout extending into the mold, and a runway for the mold, the runway being shaped so 'as to reduce the angle of inclination of the mold as the latter is moved longitudinally from the spout.

8. Apparatus as recited in claim 7 wherein the runway is also provided with a portion ascending in the direction of motion of the mold.

- 9. Apparatus as recited in claim 7 wherein the runway is also provided with a portion ascending in the direction of motion of the mold, said ascending part being movable in a vertical direction, and means for lowering said ascending part.

In testimony whereof I aflix my signature.

DR. J OHANN HOLTHAUS. 

